Effects of Isometric Wrist Torque on the Median Nerve and Its Recovery Process

Carpal tunnel syndrome (CTS) is a common neuropathy caused by increased pressure on the median nerve within the carpal tunnel. Previous studies have shown that wrist torque can lead to an increase in pressure within the carpal tunnel, and this study investigates the effects of isometric wrist torque on the cross-sectional area of the medial nerve (MNCSA) and its recovery process using ultrasound imaging. Four torque tasks were examined, including wrist flexion and extension, as well as flexion and extension without grip force to isolate the effect of grip force on the median nerve. 50% maximum voluntary torque was set as target torque level. Preliminary results indicate that the MNCSA significantly decreased during the torque tasks, exhibited incomplete recovery within 2 seconds after load removal, and formed an intriguing recovery curve. In this study, isometric wrist torque causes compressive stress on the median nerve, and results in MNCSA changes.